Prophylaxis cup having perlite particles, methods of forming and method of use

ABSTRACT

A prophylaxis cup formed of a silicone elastomer having perlite particles incorporated therein as an abrasive material. The silicone elastomer and perlite particles are processed in a 3-roll mill so that the perlite particles have a predetermined size and are uniformly dispersed throughout the prophylaxis cup. As the prophylaxis cup is used to clean and polish teeth, the prophylaxis cup disintegrates upon contact with the teeth releasing the perlite particles which act as a cleaning and polishing agent between the prophylaxis cup and the teeth.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application Ser.No. 60/482,550, filed Jun. 25, 2003.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

BACKGROUND OF THE INVENTION

(1) Field of the Invention

The present invention relates to a disposable prophylaxis cup formed ofa silicone elastomer having perlite particles incorporated therein. Thepresent invention also relates to a method of forming a prophylaxis cupof a silicone elastomer having perlite particles uniformly distributedthroughout. In addition, the present invention relates to a method ofusing a prophylaxis cup formed of a silicone elastomer having perliteparticles to clean and polish teeth.

(2) Description of the Related Art

The related art has described disposable prophylaxis cups formed of asilicone elastomer incorporated with pumice material as an abrasive foruse in cleaning teeth. Illustrative is U.S. Pat. No. 5,334,020 toEckert.

The related art has also described the use of perlite in various dentaltools as an abrasive material for cleaning teeth. Perlite is a naturallyoccurring siliceous rock. In particular, U.S. Patent ApplicationPublication 2003/0084534 A1 to Kaizuka describes a toothbrush withbristles containing a far-infrared emitting material and multi-elementminerals. One of the multi-element minerals is perlite. In addition,U.S. Patent Application Publication 2004/0074031 A1 to Davies et al.describes a toothbrush having a resilient element for whitening andpolishing the teeth. The resilient element is constructed of anelastomer into which is incorporated perlite. The perlite can be crudeor non-expanded perlite but is preferably expanded perlite.

Also of interest are U.S. Patent Application Publication Nos.2003/0224702 A1 and 2003/0203337 A1 both to Roulston which describe apolishing composition using unexpanded perlite ore and methods of usingthe polishing composition such as to polish teeth.

It is also known in the art to use perlite in prophylaxis pastes forcleaning and polishing teeth as shown in the article entitled “Advancesin Abrasive Technology in Prophylaxis Pastes”, Compendium of ContinuingEducation in Dentistry, Vol. 23: 1 (2002), pp. 61-70. 3M ESPE DentalProducts of St. Paul, Minn. manufactures a paste having perlite underthe trademark ClinPro™ Prophy.

Finally, it is known in the art to use either a 2-roll mill or a lowintensity type mixer such as a 1-arm or a 2-arm mixer to mix theabrasives into the silicone elastomer to form the compound for theprophylaxis cup. This method has worked in the past since previously theabrasives used in the prophylaxis cups were discrete particles with notendency to agglomerate. However, the use of perlite as the abrasive hasnecessitated a change in the method of forming the prophylaxis cups.

Thus, there remains a need for a disposable prophylaxis cup and for amethod for forming the prophylaxis cup where perlite particles areincorporated into the prophylaxis cup and where the prophylaxis cup whenrotating, disintegrated under load upon contact with the teeth torelease the perlite particles to clean and polish the teeth.

SUMMARY OF THE INVENTION

A prophylaxis cup formed of a silicone elastomer having perliteparticles incorporated therein as an abrasive material. To form theprophylaxis cup, the silicone and perlite particles are mixed togetherto form a compound. In one (1) embodiment, the perlite particles make upbetween about 30 and 36 percent by weight of the compound used to formthe prophylaxis cup. The compound having the silicone and perliteparticles is passed through a 3-roll mill so that the perlite particlesare reduced to a predetermined size and are evenly or uniformlydistributed throughout the prophylaxis cup. Next, the compound is placedin a preheated mold and molded under heat and pressure. The prophylaxiscup is then removed from the mold and is post-cured. Finally, theprophylaxis cup is cryogenically deflashed by bombarding the prophylaxiscup with plastic bb's. The deflashing alters the surface of theprophylaxis cup so that the prophylaxis cup begins to disintegrate morequickly during use upon contact with the teeth.

The disposable prophylaxis cup is used to clean and polish the teeth.First, the prophylaxis cup is removably mounted on a prophylaxis angleand the prophylaxis angle is activated to rotate the prophylaxis cup.Next, the prophylaxis cup is positioned on the teeth so that the axis ofthe cup is perpendicular to the surface of the tooth. The prophylaxiscup is moved along the patient's teeth from tooth to tooth. As theprophylaxis cup is moved along the patient's teeth, the rotationalcontact of the prophylaxis cup with the teeth under load causes theprophylaxis cup to disintegrate. As the prophylaxis cup disintegrates,the perlite particles are separated from the prophylaxis cup. Theperlite particles and the moisture on the teeth form a slurry betweenthe prophylaxis cup and the teeth. As the prophylaxis cup is moved alongthe teeth, the slurry acts as a cleaning and polishing agent and removesstains from the teeth. The perlite particles in the slurry continue tocontact the teeth and break down into smaller perlite particles. Thesmaller perlite particles act as a polishing agent for the final stageof the polishing procedure.

The present invention relates to a disposable prophylaxis cup forcleaning and polishing teeth, which comprises: a silicone elastomer; andperlite particles incorporated in the silicone elastomer as an abrasivematerial.

Further, the present invention relates to a method for cleaning andpolishing teeth, which comprises the steps of: providing a disposableprophylaxis cup including a silicone elastomer having perlite particlesas an abrasive material incorporated therein; providing a prophylaxisangle; mounting the prophylaxis cup on the prophylaxis angle;positioning the prophylaxis cup adjacent the teeth; activating theprophylaxis angle such that the prophylaxis cup rotates; moving theprophylaxis cup into contact with the teeth wherein the prophylaxis cupbegins to disintegrate and the perlite particles in the prophylaxis cupare gradually separated from the prophylaxis cup so that a slurry havingthe perlite particles is formed between the teeth and the prophylaxiscup; and moving the prophylaxis cup along the teeth wherein the slurrybetween the prophylaxis cup and the teeth acts as a cleaning andpolishing agent to clean and polish the teeth as the prophylaxis cup ismoved along the teeth.

Still further, the present invention relates to a method for forming aprophylaxis cup which comprises the steps of: providing a siliconeelastomer; providing perlite particles; mixing the silicone elastomerand the perlite particles so that the perlite particles are evenlydispersed into the silicone elastomer to produce a compound; providing a3-roll mill; passing the compound through the 3-roll mill at least twiceto achieve separation of any agglomerated perlite particles and toproduce uniform dispersion of the perlite particles in the siliconeelastomer; loading the compound into the mold and closing the moldaround the compound; removing the prophylaxis cup from the mold; postcuring the prophylaxis cup; and deflashing the prophylaxis cup using acryogenic deflashing system.

The substance and advantages of the present invention will becomeincreasingly apparent by reference to the following drawings and thedescription.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional side view of the prophylaxis cup 10 of thepresent invention mounted on a prophylaxis angle 150.

FIG. 2 is a side view showing the prophylaxis cup 10 in contact with atooth 20 and showing the slurry 30 having the perlite particles 52 andthe smaller perlite particles 54.

FIG. 3 is a schematic diagram of the 3-roll mill 100.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows the flexible prophylaxis cup 10 of the present inventionused for cleaning and polishing teeth 20. The prophylaxis cup 10 isconstructed of a compound having a silicone elastomer material 50 toenable the prophylaxis cup 10 to be flexible and perlite particles 52 toprovide the abrasion necessary to clean and polish the teeth 20. Theperlite particles 52 in the prophylaxis cup 10 enable the prophylaxiscup 10 to be used on teeth 20 to remove stains and to produce a highpolish. Since the prophylaxis cup 10 incorporates an abrasive materialdistributed evenly throughout, there is no need to use a dental paste incombination with the prophylaxis cup 10. One (1) of the benefits ofusing perlite is that perlite is significantly less abrasive than anyother abrasives used for teeth cleaning. The prophylaxis cup 10 of thepresent invention is particularly effective for use in pediatric dentalcare. In one (1) embodiment, the silicone elastomer material 50 isplatinum cured methyl vinyl siloxane and the perlite particles 52 areGrade FA expanded perlite.

To produce the prophylaxis cups 10, the silicone elastomer 50 and theperlite particles 52 must be mixed together into a compound. Before thesilicone elastomer 50 and the perlite particles 52 are mixed together toform the compound, the silicone elastomer 50 and the perlite particles52 are weighed using a triple beam balance or equivalent scales toachieve the correct formulation. In one (1) embodiment, the perliteparticles 52 make up between about 30 and 36 percent by weight of thecompound used to form the prophylaxis cup 10. Testing of compoundshaving varying percentages by weight of perlite particles 52, found thata prophylaxis cup 10 produced with a compound having less than 20percent by weight of perlite particles 52 maintained its integrityduring use but did not successfully polish or clean teeth 20. Aprophylaxis cup 10 formed from a compound having approximately 20percent by weight of perlite particles 52 maintained its integrity whileremoving plaque and mild or light stains as well as polishing the teeth20. It was found that a prophylaxis cup 10 formed from a compound havingbetween about 20 to 25 percent by weight of perlite particles 52 wassuccessful for cleaning and polishing children's teeth. A prophylaxiscup 10 produced from a compound having between approximately 25 and 28percent by weight of perlite particles 52 maintained its integrity andremoved plaque and moderate stains as well as polishing the teeth 20. Aprophylaxis cup 10 produced from a compound having approximately 33percent by weight of perlite particles 52 removed plaque as well asheavy stains and also polished teeth 20. A prophylaxis cup 10 having 36percent or greater by weight of perlite particles 52 disintegrated toorapidly during use and was unable to complete a standard prophylaxisprocedure. It is understood that the prophylaxis cup 10 will wear downor disintegrate during normal use. To be successful, the prophylaxis cup10 must be able to complete a standard dental prophylaxis procedurewithout disintegrating to the point that the prophylaxis cup 10 can nolonger be used. A single prophylaxis cup 10 is disposable and intendedfor single use. A single prophylaxis cleaning and polishing procedurenormally takes between about 4 and 15 minutes.

Once the correct amounts of silicone elastomer 50 and perlite particles52 have been determined, the next step is to mix the perlite particles52 into the silicone elastomer 50. The perlite particles 52 are mixedinto the silicone elastomer 50 using a 2-roll mill, 1 arm or 2 arm mixeror equivalent piece of equipment so that the perlite particles 52 aredispersed into the silicone elastomer 50. The combined siliconeelastomer 50 and perlite compound is then passed through a 3-roll mill100, or high intensity mixer so that any of the perlite particles 52which have agglomerated are separated into perlite particles 52 within apredetermined size range and evenly or uniformly dispersed throughoutthe silicone elastomer 50 (FIG. 3). The use of perlite particles 52 asthe abrasive material in the prophylaxis cup 10 has necessitated achange in the processing of the compound to provide the prophylaxis cup10. The perlite particles 52 form agglomerates and must be mixed orcompounded into the silicone elastomer 50 using either a size reductionmethod or high intensity mixer. One (1) way of accomplishing this is touse a 3-roll mill 100. Another method would be to utilize one (1) ofseveral types of high intensity internal mixers. This additional stepensures that any agglomeration of perlite particles 52 are separatedsufficiently so that the resulting perlite particles 52 will be withinthe predetermined size range and will be evenly dispersed into the finalmolded prophylaxis cup 10. Evenly dispersing the perlite particles 52throughout the prophylaxis cup 10 provides for even wear and uniformdisintegration of the prophylaxis cup 10 during the use of theprophylaxis cup 10. In addition, providing a uniform starting particlesize of the perlite particle 52 in the prophylaxis cup 10 producesoptimal stain removal and polishing. In one (1) embodiment, the perliteparticles 52 achieve an average particle size of between approximately15 and 40 microns during the processing.

In one (1) embodiment using a 3-roll mill 100, the compound is passedthrough the 3-roll mill 100 at least twice to uniformly disperse theperlite particles 52 throughout the silicone elastomer 50. The three (3)rollers 102, 104 and 106 of the 3-roll mill 100 are rotating atdifferent rates of speed so that a shearing effect is produced in thecompound as the compound moves between the rollers 102, 104 and 106. Theshearing action breaks down any agglomeration of perlite particles 52 towithin the range of predetermined size and helps to disperse the perliteparticles 52 uniformly throughout the silicone elastomer 50. In one (1)embodiment, the first roller 102 is the slowest and the last roller 106is the fastest. In one (1) embodiment, the first roller 102 rotates at aspeed of approximately 20 rpm, the second roller 104 rotates at a speedof approximately 30 rpm and the third roller 106 rotates at a speed ofapproximately 40 rpm. In one (1) embodiment, cheek plates are providednear each end of the rollers 102, 104 and 106, and act to funnel orguide the compound between the rollers 102, 104 and 106. An initial passthrough the mill 100 can be done with the roll separation or “nip”between the first and second rollers 102 and 104 and the second andthird rollers 104 and 106 set at approximately 120 microns. The secondand subsequent passes through the 3-roll mill 100 are done with thefirst nip 108 between the first and second rollers 102 and 104 set at120 microns and the second nip 110 between the second and third rollers104 and 106 set at about 80 and 40 microns for the second and subsequentpasses, respectively (FIG. 3). In one (1) embodiment for the initial orfirst pass, the first nip 108 or roll separation between the first andsecond rollers 102 and 104 is set at approximately 125 microns and thesecond nip 110 or roll separation between the second and third rollers104 and 106 is set at approximately 100 microns. For the second pass,the first nip 108 is set at approximately 120 microns and the second nip110 is set at approximately 50 microns. For the final or third pass, thefirst nip 108 is set at approximately 120 microns and the second nip 110is set at approximately 25 microns. The mill 100 should be cleanedbetween each pass to ensure consistency of the compound. A scraper 112is positioned adjacent the third roller 106 and acts to remove thecompound from the third roller 106 and out of the 3-roll mill 100.

Once the compound is thoroughly mixed, the compound is ready formolding. The compound is weighed into amounts suitable for the moldbeing used. In one (1) embodiment, the mold is preheated to betweenabout 260° F. and 340° F. (127° C. and 171 ° C.). The compound is loadedinto the mold and the mold closed. The compound remains in the mold forbetween about 1 to 3 minutes. The mold is then opened and theprophylaxis cup or cups 10 are removed. The prophylaxis cups 10 are thenpost cured for approximately 3 hours at about 280° F. (138° C.) in are-circulating oven with a minimum of 1.9 ft³/minute of new air flow perpound of silicone prophylaxis cups 10 present in the oven. Theprophylaxis cups 10 are inspected for deformities and discoloration andare de-flashed using a cryogenic de-flashing system. In one (1)embodiment, the mold is a compression mold and the prophylaxis cups 10are formed using heat and the compression of the plates of the mold. Inanother embodiment, the prophylaxis cups 10 are formed using injectionmolding.

In one (1) embodiment, to deflash the prophylaxis cups 10, theprophylaxis cups 10 are frozen to between about −180° F. to −200° F.(−118° C. to −129° C.). In one (1) embodiment, the prophylaxis cups 10are frozen by placing the prophylaxis cups 10 in Nitrogen vapor. Whilethe prophylaxis cups 10 are frozen, the prophylaxis cups 10 arebombarded with objects to remove the flash. In one (1) embodiment, theobjects are plastic bb's. In one (1) embodiment, the prophylaxis cups 10are bombarded for between about 8 to 15 minutes, depending upon theamount of flash to be removed. Once the flash is removed, theprophylaxis cups 10 are warmed to room temperature. In one (1)embodiment, during the deflashing, the bombardment of the prophylaxiscups 10 removes the case hardened surface of the prophylaxis cup 10caused by the molding process. The deflashing process produces a mattefinish on the surface of the prophylaxis cup 10. The deflashing processalters the surface of the prophylaxis cup 10 so that the prophylaxis cup10 begins to disintegrate more quickly and the perlite particles 52separate from the prophylaxis cup 10 more quickly upon contact with theteeth 20. For prophylaxis cups 10 having perlite particles 52 which areprocessed using this deflashing process, the prophylaxis cup 10 beginsto disintegrate and the perlite particles 52 begin to separate from theprophylaxis cup 10 less than 10 seconds after initial rotational, in usecontact of the prophylaxis cup 10 with the teeth 20. In one (1)embodiment, the prophylaxis cup 10 having perlite particles 52 begins todisintegrate and the perlite particles 52 begin to separate from theprophylaxis cup 10 about 5 seconds after initial rotational, in usecontact of the prophylaxis cup 10 with the teeth 20.

The disposable prophylaxis cup 10 is intended to be mounted on aprophylaxis angle 150. One (1) method of mounting the prophylaxis cup 10on the prophylaxis angle 150 is described in U.S. Pat. No. 5,334,020 toEckert which is incorporated herein in its entirety by reference.However, it is understood that any well known means of mounting theprophylaxis cup 10 to the prophylaxis angle 150 can be used. Theprophylaxis cup 10 can be used with a disposable prophylaxis angle or anon-disposable prophylaxis angle 150.

To use the prophylaxis cup 10 to clean and polish teeth 20, theprophylaxis cup 10 is positioned on the surface 20A of the tooth 20(FIG. 2). In one (1) embodiment, initially the prophylaxis cup 10 ispositioned on the surface 20A of the tooth 20 so that an axis of theprophylaxis cup 10 is perpendicular to the surface 20A of the tooth 20.The prophylaxis angle 150 is then activated so that the prophylaxis cup10 rotates. The user then applies pressure on the tooth 20 so that theprophylaxis cup 10 deforms on the surface 20A of the tooth 20 so thatthe surface 20A of the tooth 20 contacts the inner surface of theprophylaxis cup 10. The prophylaxis cup 10 is moved along the teeth 20so that the prophylaxis cup 10 cleans and polishes the surfaces 20A ofeach tooth 20 individually. During cleaning, the prophylaxis cup 10 maybe positioned so that all sides of the prophylaxis cup 10 may be used toclean and polish the surfaces 20A of the tooth 20. In one (1)embodiment, the prophylaxis cup 10 is placed in contact with the tooth20 and then the prophylaxis angle 150 is activated to rotate theprophylaxis cup 10. In another embodiment, the prophylaxis angle 150 isactivated first so that the prophylaxis cup 10 is rotating when theprophylaxis cup 10 makes contact with the surface 20A of the tooth 20.As the prophylaxis cup 10 spins on the surface 20A of the tooth 20 underload, the prophylaxis cup 10 disintegrates and the perlite particles 52adjacent to the surface 20A of the tooth 20 are liberated or separatedfrom the prophylaxis cup 10. In one (1) embodiment, the prophylaxis cup10 begins to disintegrate and the perlite particles 52 begin to separatefrom the prophylaxis cup 10 less than 10 seconds after the rotatingprophylaxis cup 10 makes initial contact with the surface 20A of thetooth 20 under load during use. In one (1) embodiment, the prophylaxiscup 10 begins to disintegrate and the perlite particles 52 begin toseparate from the prophylaxis cup 10 approximately 5 seconds after therotating prophylaxis cup 10 makes initial contact with the surface 20Aof the tooth 20 under load during use. The liberated perlite particles52 mix with the moisture or saliva on the tooth 20 and form a slurry 30between the prophylaxis cup 10 and the surface 20A of the tooth 20. Theslurry 30 acts as a cleaning and polishing agent. As the prophylaxis cup10 breaks down, the silicone elastomer 50 is also released and becomespart of the slurry 30. As the user continues to apply pressure on theprophylaxis cup 10 on the surface 20A of the tooth 20 and theprophylaxis cup 10 continues to rotate on the surface 20A of the tooth20, the perlite particles 52 in the slurry 30 contact the surface 20A ofthe tooth 20 and remove heavier stains from the surface 20A of the tooth20. The first stage of cleaning the teeth 20 involves the removal ofstains from the teeth 20. The perlite particles 52 initially releasedfrom the prophylaxis cup 10 have a size between about 15 and 40 microns.As the perlite particles 52 in the slurry 30 continually contact thesurface 20A of the tooth 20, the perlite particles 52 fracture or breakdown into smaller particles 54. The expanded perlite particles 52 arevery fragile and easily break down upon contact with the enamel on thesurface 20A of the teeth 20. The rotation of the prophylaxis cup 10 onthe surface 20A of the teeth 20 under load causes the smaller perliteparticles 54 to rub against the surface 20A of the teeth 20 producing ahighly polished surface. This completes the second, polishing stage ofcleaning. In one (1) embodiment during the polishing stage, the smallerperlite particles 54 have a size less than 15 microns. The prophylaxiscup 10 continues to disintegrate throughout the prophylaxis cleaning andpolishing procedure. The uniform distribution of the perlite particles52 throughout the prophylaxis cup 10 enables the prophylaxis cup 10 tocontinue to clean and polish throughout the entire prophylaxisprocedure. In one (1) embodiment, a standard and prophylaxis cleaningprocedure lasts between about 4 to 15 minutes. It is understood that asecond cup 10 could be used for heavy duty prophylaxis cleaning andpolishing procedures. Once the teeth 20 are cleaned and polished, theprophylaxis cup 10 is removed and the slurry 30 is evacuated from themouth of the patient. However, it is understood that all the materialsin the prophylaxis cup 10 are inert and are not harmful to a patient ifswallowed.

It is intended that the foregoing description be only illustrative ofthe present invention and that the present invention be limited only bythe hereinafter appended claims.

1. A disposable prophylaxis cup for cleaning and polishing teeth, whichcomprises: (a) a silicone elastomer; and (b) perlite particlesincorporated in the silicone elastomer as an abrasive material.
 2. Thecup of claim 1 wherein the perlite particles in the prophylaxis cup havea size of between about 15 and 40 microns.
 3. The cup of claim 1 whereinthe prophylaxis cup disintegrates when the prophylaxis cup rotatesagainst a surface of the teeth so that the perlite particles areseparated from the prophylaxis cup when the prophylaxis cup contacts theteeth.
 4. The cup of claim 3 wherein the perlite particles in theprophylaxis cup have a size of between about 15 and 40 microns and wherethe size of the perlite particles decreases as the perlite particlesseparated from the prophylaxis cup contact the teeth.
 5. The cup ofclaim 1 wherein the perlite particles are uniformly dispersed throughoutthe silicone elastomer in the prophylaxis cup.
 6. The cup of claim 1wherein the perlite particles are between about 30 and 36 percent byweight of the prophylaxis cup.
 7. The cup of claim 1 wherein theprophylaxis cup begins to disintegrate and the perlite particles beginto separate from the prophylaxis cup between about 5 and 10 secondsafter the prophylaxis cup begins to rotate against a surface of theteeth.
 8. The cup of claim 1 wherein the prophylaxis cup is mounted on adisposable prophylaxis angle.
 9. A method for cleaning and polishingteeth, which comprises the steps of: (a) providing a disposableprophylaxis cup including a silicone elastomer having perlite particlesas an abrasive material incorporated therein; (b) providing aprophylaxis angle; (c) mounting the prophylaxis cup on the prophylaxisangle; (d) positioning the prophylaxis cup adjacent the teeth; (e)activating the prophylaxis angle such that the prophylaxis cup rotates;(f) moving the prophylaxis cup into contact with the teeth wherein theprophylaxis cup begins to disintegrate and the perlite particles in theprophylaxis cup are gradually separated from the prophylaxis cup so thata slurry having the perlite particles is formed between the teeth andthe prophylaxis cup; and (g) moving the prophylaxis cup along the teethwherein the slurry between the prophylaxis cup and the teeth acts as acleaning and polishing agent to clean and polish the teeth as theprophylaxis cup is moved along the teeth.
 10. The method of claim 9wherein in step (f), the prophylaxis cup begins to disintegrate and theperlite particles separate from the prophylaxis cup approximately 5seconds after initial, rotational contact of the prophylaxis cup withthe teeth.
 11. The method of claim 9 wherein in step (f), theprophylaxis cup begins to disintegrate and the perlite particlesseparate from the prophylaxis cup less than 10 seconds after initial,rotational contact of the prophylaxis cup with the teeth.
 12. The methodof claim 9 wherein in step (g), the prophylaxis cup is moved along theteeth for between about 4 and 15 minutes to clean and polish each toothindividually until the cleaning and polishing of the teeth is completed.13. The method of claim 9 wherein the prophylaxis cup is in contact withthe teeth prior to activating the prophylaxis angle and wherein in step(f), the prophylaxis cup does not begin to disintegrate until theprophylaxis cup is rotating.
 14. The method of claim 9 wherein afterstep (g), the slurry is evacuated from a user's mouth.
 15. The method ofclaim 9 wherein further in step (g), as the slurry is moved over theteeth by the prophylaxis cup, the perlite particles in the slurry arebroken down into smaller perlite particles.
 16. The method of claim 15wherein the smaller perlite particles act to polish the teeth.
 17. Themethod of claim 9 wherein in step (f), the perlite particles initiallyseparated from the prophylaxis cup and have a size of between about 15and 40 microns.
 18. The method of claim 9 wherein in step (g), theperlite particles in the slurry act as an abrasive to remove stains fromthe teeth. 19-29. (canceled)